[Pkg-sysvinit-devel] A wish for help with Bug#765803 On automatic init system switching on upgrade

[Svante Signell]

On Fri, 2014-11-21 at 20:20 +0000, Thorsten Glaser wrote:
> Petter Reinholdtsen dixit:
> 
> >That is correct.  But one can change the behaviour of future
> >installations after asking and then interrupting the upgrade and
> >requiring a new upgrade.  Not the best user experience, but it might be
> 
> No, no, no, no, no! Absolutely not.
> 
> If you abort in such a script, the user has to manually play
> around with dpkg-reconfigure, dpkg --remove or --purge, and
> apt-get -f install, which will in some cases fail to DWYW,
> or even remove half the system.
> 
> >Check in the config script which boot system is being used, and if it is
> >sysvinit, ask if it is ok to switch to systemd.  If the answer is no,
> >write a file /etc/apt/preferences.d/no-systemd with the content
> 
> No, too late.
> 
> >abort the upgrade
> 
> Absolutely not, see above.
> 
> >Definitely not a good user experience, but perhaps that can be improved?
> 
> I’d classify it as catastrophic fail. It is probably actually better
> to let apt continue to temporarily install systemd and then have the
> user remove that later.

Taking your comments and the freeze into consideration the text below
is a proposal how this can be (unfortunately sub-optimally) solved.

The ways out of this I can see now are two (three) fronts:

1) Heavily advertise (where?) that doing an upgrade to jessie will give
you systemd as init system and inform about the apt pinning solution.

2) In case you missed doing the above, you get a debconf prompt when
installing the init package that if you want to keep sysv/openrc/etc
continue with the installation, get systemd-sysv installed and after
completed installatiion and reboot install sysvinit-core and do the
pinning. (This is suboptimal, many peoples systems could be broken at
first reboot, we will find out in due time).

Another issue is upgrading from testing (different status) to jessie:
3) Heavily advertise (again where?) that you need to install
sysvinit-core and add the pinning file _before_ dist-upgrading.

Not much technical in this, except creating a (non-aborting) debconf
prompt during the installation. Can this (when refined) be presented to
the TC, or is there a need to implement all this and have verified
results?